The study compromised 23 advanced EGFR T790M-mutated NSCLC patients...TP53 was the most common co-occurring mutations and led to shorter osimertinib-related PFS (mPFS for patients with or without TP53 co-mutation were 8.00±1.02 and 15.00±4.43months, HR=4.40, 95%CI: 0.82-23.49, log-rank P=0.042).